A group-based PDCCH capability is proposed in LTE. In particular, information common to a group of UEs, such as those common to a virtual carrier, may be signalled in a group search space within the PDCCH. This common information may include the location of a further control region embedded in the virtual carrier which contains UE-specific information for access the resources of the virtual carrier. Additional methods are introduced for assigning UEs a group identity by implicit signalling, and for determining the aggregation level of the group-based PDCCH search space.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A wireless communications system for transmitting data to and/or receiving data from mobile terminals, the wireless communications system comprising: one or more base stations, each of which includes a transmitter and a receiver configured to provide a wireless access interface for communicating data to and/or from the mobile terminals, the wireless access interface providing a plurality of communications resource elements across a first frequency range, wherein the wireless access interface provided by the one or more base stations includes a plurality of time divided sub-frames, and at least one of the sub-frames includes: a first control region in a first part of the sub-frame for communicating first signaling information to one or more of the mobile terminals, the first control region including a plurality of control channel resource elements, a first subset of said control channel resource elements providing a group control channel, the group control channel being associated with a group identifier and at least partially encoded using the group identifier, and a second control region in a second part of the sub-frame, distinct from the first part of the sub-frame, the second control region being for communicating second signaling information to a predetermined group of the mobile terminals, the group control channel contains information indicative of the location of the second control region, said information being accessible by applying the group identifier to the group control channel and each of the predetermined group of mobile terminals uses the group identifier, and the group identifier is deduced from a relationship between a first preamble signature indicated in a random access preamble message received by a base station from a terminal and a second preamble signature indicated in a random access response message transmitted by the base station to the terminal in reply to the random access preamble message.
2. The wireless communications system as claimed in claim 1 , wherein the first part of the sub-frame is transmitted before the second part.
3. The wireless communications system as claimed in claim 1 , wherein the group identifier is a radio network temporary identifier (RNTI) and the encoding of the group control channel is the encoding of cyclical redundancy code (CRC) bits using the RNTI.
4. The wireless communications system as claimed in claim 1 , wherein the group identifier is determined to be a temporary radio network temporary identifier (RNTI) assigned to the communications device by one of said base stations.
5. The wireless communications system as claimed in claim 1 , wherein the random access response message transmitted by the base station in reply to the random access preamble message includes a reserved RNTI where a cell RNTI is expected, and wherein the group identifier is determined by the terminal to be the reserved RNTI by virtue of the presence of the reserved RNTI in the random access response message.
6. The wireless communications system as claimed in claim 1 , wherein the second control region is a narrow band control region, having a second bandwidth which is less than the bandwidth of the first control region.
7. The wireless communications system as claimed in claim 6 , wherein said second control region is a region within a third region, the third region being distinct from the first control region, the third region having a third bandwidth which is less than the bandwidth of the first control region and greater than or equal to the second bandwidth, the third region being configured for communicating data to one or more of the mobile terminals.
8. The wireless communications system as claimed in claim 7 , wherein said third region includes a fourth region, the fourth region having a fourth bandwidth which is less than the third bandwidth, the fourth region being configured for communicating further control data to one or more of the mobile terminals.
9. The wireless communications system as claimed in claim 8 , wherein said fourth region extends across all of the duration of the second part of the sub-frame external to the second control region.
10. The wireless communications system as claimed in claim 1 , wherein the control channel resource elements of the group control channel have an associated aggregation level, wherein a second subset of said control channel resource elements in the first control region provide at least one further control channel, the control channel resource elements of the or each further control channel having an associated further aggregation level, and wherein said aggregation level is a function of at least one of the further aggregation levels.
11. The wireless communications system as claimed in claim 1 , wherein the control channel resource elements of the group control channel have an associated aggregation level, and wherein the aggregation level is broadcast.
12. The wireless communications system as claimed in claim 1 , wherein the control channel resource elements of the group control channel have an associated aggregation level, wherein the aggregation level is determined by the base station according to feedback information from the mobile terminals, and wherein the feedback information corresponds to acknowledgement of receipt.
13. The wireless communications system as claimed in claim 12 , wherein the feedback information is the result of a comparison between an expected rate of receipt of acknowledgements and a detected rate of receipt of acknowledgements.
14. A network element for a mobile communications network for transmitting data to and/or receiving data from mobile terminals, the network element comprising: a transmitter and a receiver configured to provide a wireless access interface for communicating data to and/or from the mobile terminals, the wireless access interface providing a plurality of communications resource elements across a first frequency range, wherein the wireless access interface provided by the network element includes a plurality of time divided sub-frames, and at least one of the sub-frames includes: a first control region in a first part of the sub-frame for communicating first signaling information to one or more of the mobile terminals, the first control region including a plurality of control channel resource elements, a first subset of said control channel resource elements providing a group control channel, the group control channel being associated with a group identifier and at least partially encoded using the group identifier, and a second control region in a second part of the sub-frame, distinct from the first part of the sub-frame, the second control region being for communicating second signaling information to a predetermined group of the mobile terminals, the group control channel contains information indicative of the location of the second control region, said information being accessible by applying the group identifier to the group control channel and each of the predetermined group of mobile terminals uses the group identifier, and the group identifier is deduced from a relationship between a first preamble signature indicated in a random access preamble message received by a base station from a terminal and a second preamble signature indicated in a random access response message transmitted by the base station to the terminal in reply to the random access preamble message.
15. The network element as claimed in claim 14 , wherein the first part of the subframe is transmitted before the second part.
16. The A network element as claimed in claim 14 , wherein the group identifier is a radio network temporary identifier (RNTI) and the encoding of the group control channel is the encoding of cyclical redundancy code (CRC) bits using the RNTI.
17. The network element as claimed in claim 14 , wherein the group identifier is determined to be a temporary radio network temporary identifier (RNTI) assigned to the communications device by one of a plurality of base stations.
18. The network element as claimed in claim 14 , wherein the random access response message transmitted by the base station in reply to the random access preamble message includes a reserved RNTI where a cell RNTI is expected, and wherein the group identifier is determined by the terminal to be the reserved RNTI by virtue of the presence of the reserved RNTI in the random access response message.
19. The network element as claimed in claim 14 , wherein the second control region is a narrow band control region, having a second bandwidth which is less than the bandwidth of the first control region.
20. The network element as claimed in claim 19 , wherein said second control region is a region within a third region, the third region being distinct from the first control region, the third region having a third bandwidth which is less than the bandwidth of the first control region and greater than or equal to the second bandwidth, the third region being configured for communicating data to one or more of the mobile terminals.
21. The network element as claimed in claim 20 , wherein said third region includes a fourth region, the fourth region having a fourth bandwidth which is less than the third bandwidth, the fourth region being configured for communicating further control data to one or more of the mobile terminals.
22. The network element as claimed in claim 21 , wherein said fourth region extends across all of the duration of the second part of the subframe external to the second control region.
23. A method of operating a wireless communications system for transmitting data to and/or receiving data from mobile terminals, the method comprising: providing a plurality of communications resource elements across a first frequency range, wherein the plurality of communications resource elements are arranged in a plurality of time divided sub-frames, and at least one of the sub-frames includes: a first control region in a first part of the sub-frame for communicating first signaling information to one or more of the mobile terminals, the first control region including a plurality of control channel resource elements, a first subset of said control channel resource elements providing a group control channel, the group control channel being associated with a group identifier and at least partially encoded using the group identifier, and a second control region in a second part of the sub-frame, distinct from the first part of the sub-frame, the second control region being for communicating second signaling information to a predetermined group of the mobile terminals, the group control channel contains information indicative of the location of the second control region, said information being accessible by applying the group identifier to the group control channel and each of the predetermined group of mobile terminals uses the group identifier, and the group identifier is deduced from a relationship between a first preamble signature indicated in a random access preamble message received by a base station from a terminal and a second preamble signature indicated in a random access response message transmitted by the base station to the terminal in reply to the random access preamble message.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
December 28, 2018
May 19, 2020
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.